¿ is height really might?

[Wire Dawg]

Finally got a used tower, raised it & put my M104c up at 41 feet (last Sunday). Expected that the great Tx/ Rx I had when the antenna was at 27’ high, was going to reach Dx nirvana at 41’. Instead, the few stations I used to contact at 1800 miles, which had nothing but praises for my signal, now tell me they can barely read me. Their signals are just a whisper above the noise floor in my radio (were 5/9 before). I put a new/ shorter run of RG 213, new connectors & one extra turn on the ugly balun. Guy wires are broken by insulators. SWR is better than before, maybe due to better grounding. Have the atmospheric conditions changed so much in just two days, or is the additional height working against me? What else can explain the degradation?

 

[Shockwave]

DX signals are notoriously unstable and usually poor indicators of how an antenna is performing. If improving this area was your goal, I would give it a few more days to get more of an average idea of how its working. Changing height does change the angle of radiation on your antenna and this does affect the "target area" of your antenna. However, I don't think going from 27 to 41 feet would cause the results you are seeing.

 

[Wire Dawg]

Thanks for the positive comments. I hope is just the "conditions" for the last two days, and that these will improve soon. I'd be very disappointed if I had to disassemble the set up.

 

[RADIOOMAN]

Two days might be a little too soon to rush to judgement.

Consider leaving it where it is and get another and put it where the other one was, and then you have a better way to compare.

 

[Beetle]

The mention of your SWR being much better now leads me to think about the coax and/or the antenna itself. Saying you have "better" SWR can mean "it's more like a dummy load than before".

If you haven't already done it, get hold of an antenna analyzer and sweep the band, recording readings (SWR, resistance and impedance). Things SHOULD be no worse than they were earlier. Low SWR, by itself, is no indication of how well an antenna is performing.

 

[Wire Dawg]

The mention of your SWR being much better now leads me to think about the coax and/or the antenna itself. Saying you have "better" SWR can mean "it's more like a dummy load than before".

Best SWR prior to raising the antenna was 1.3:1 while highest was 1.7:1. Although I do not believe that 1:1 can be achieved, I must say that at the upper frequencies, the SWR meter does not show any reflected (on two different meters), and the highest swr is now 1.5:1. Readings were taken at 10W out. I will wait for this bad weather to dissipate (hopefuly no snow). Thanks!

 

[Captain Kilowatt]

Sounds like you made the same common mistake a lot of people do. You cannot judge changes on DX signals over a few days. It takes weeks or months to see the overall picture. DX can be hammering today and barely there tomorrow. The idea is to compare the overall performance and don't expect anything dramatic.

 

[ghutch]

Would adding the few feet change the radiation pattern.? Would the radiation angle create a lobe with nulls that could result in less signal from a particular local? Someone might model the antenna an see if a pattern change has happened.

 

[Captain Kilowatt]

Propagation is far from consistent from one hour to tbe next much less from one day to the next. You absolutely cannot have meaningful results from one or two days of use. I used to have a daily schedule with a station in Sao Paulo Brazil. Some days Ismeal was 59+ and others he was 33. Nothing changed except for Mother Nature. We had over 125 contacts BTW on which to base that.

 

[W5LZ]

What differences you seen to this point are probably about normal. Nothing earth shattering, but you really shouldn't expect much of that anyway. I seriously doubt if you will ever see a really dramatic benefit from increased height of an antenna unless where it was previously was really terrible.
After you give it some time so that you have an idea of what's happening, I think you will see that you've expanded your 'hearing' by some degree. How big a degree? How would I, or anyone else, be able to tell you that? Just way too many 'possibilities' with just propagation affects, who'z where and doing any talking, and what's on TV, you know?
Don't get discouraged too soon!
- 'Doc

 

[Henry HPSD]

It most certainly is. (heigth = migth)
especially when the band just opens....or when the sunspots are low.
especially for those real long distance qso's.


With that said..when the band is just "open" you can work the world using a needle at ground level.

perhaps some usefull information:

http://www.hpsd.nl/wp-content/uploads/2012/10/HPSD-3el-1-1-heigth-versus-take-off-angle.pdf

and:
Height versus take off angle

Kind regards,

Henry 19sd348

 

[hotrod]

using the dx contacts theory is the worst way to judge antenna performance.
you can talk skip on a piece of wire if conditions are right. should,ve checked
it locally either with other bases o going out 30-40 miles in a mobile take
s-meters readings. then swap and do same thing.thats how i do mine
maybe not the most sciencetist method but it shows me what i wanna know.
the bigger thing is you say your swr went down USUALLY lenth of coax shouldnt
affect swr not enough to see on meter imho

 

[Wire Dawg]

Thanks again. I had never been able to 'hear' Colombia, and I just completed a short QSO with a station in Bucaramanga (first time). W5LZ is right about been able to hear more stations. I got a good report. I will continue to wait for the weather to improve, and hope to get back the reports I was getting from my old contacts.

 

[project]

I went from 40' to 160' and it made a huge difference in contacts.

 

[Captain Kilowatt]

I went from 40' to 160' and it made a huge difference in contacts.

That's just a bit different than going from 27' to 41'.If it didn't make a huge difference I would say you have HUGE issues.